In traditional brush plating processes, a positively charged anode is closely positioned to a negatively charged conductive substrate which functions as a cathode. An absorbent wrapping, incorporated within the anode, is wrapped about the surface of the substrate. In turn, an electroplating solution having metallic ions is supplied to the wrapping and thereby made available to the substrate. A direct electric potential is applied between the anode and the substrate to cause the positively charged metallic ions to be deposited from the electroplating solution onto the surface of the substrate.
Unfortunately, with present systems, it has been difficult, if not impossible, to achieve thick, dense metallic depositions that are free of structural flaws. Thick metal depositions may be obtained in several layering steps, but these depositions are either rough or can include defects or have inferior bonding strength between layers as the deposition becomes thicker.
Accordingly, what is needed in the art is an improved method and apparatus for electroplating a relatively thick, substantially defect-free metallic deposition onto a conductive substrate.